Extensive pipeline systems exist for carrying gas or liquid under pressure over long distances. These pipelines are subject to corrosion from the outside as a result of moisture from the surrounding environment and/or from the inside due to the fluid or gas being transported. The corrosion thins the walls of the pipeline, which can eventually lead to the leaking of fluid or gas. Because the contents of the pipeline are under pressure, any leak will rapidly increase in volume.
Weakened sections of pipeline may be discovered through inspections of the pipeline. Once discovered, various methods exist for externally patching pipelines to repair leaks or reinforce sections of the pipeline with walls that have thinned from corrosion. Repair methods that allow for the pipeline to continue operation without interruption are particularly valuable because of the revenue that is lost by the pipeline owner from any flow interruption, in addition to the problems resulting from supply disruptions to end users of the product flowing through the pipeline.